Hi all,
For a cheaper alternative to the heavy plastic mesh you can use Dry Wall tape. Any hardware store will have it and sometimes craft shops are not around. The roll will be about 5 or 6 bucks but I have already used the one in the picture for about 12 plants and it still has about 50 more uses in it. At least. Its made from strong but very thin plastic. Before writing this I whent and checked all the plants that I've used this for and the mesh has not sagged on any. One of the plants is a huge rubber tree that has over six quarts of potting soil and an big root system on top of it.
Plus my favorite part is the mesh tape has a low tack side the adheres extremely well to a dry pot and does not budge or leave any residue.(you can see I stuck it to my computer for the pic) Remember its made for a heavy wet joint compound to be push into it and dried then sanded with out it moving of warping in any way!
Good luck and thanks for reading!
Anthony